Buggy code:
public class ConnectorServices { private static Map < String , Set < ServiceName > > resourceAdapterServiceNames = new HashMap < String , Set < ServiceName > > ( ) ; private static Map < String , Set < Integer > > resourceAdapterIdentifiers = new HashMap < String , Set < Integer > > ( ) ; private static Map < String , ServiceName > deploymentServiceNames = new HashMap < String , ServiceName > ( ) ; private static Map < String , Set < Integer > > deploymentIdentifiers = new HashMap < String , Set < Integer > > ( ) ; private static Map < String , Set < Integer > > resourceIdentifiers = new HashMap < String , Set < Integer > > ( ) ; private static Map < String , String > resourceAdapterRepositoryIdentifiers = new HashMap < String , String > ( ) ; public static final ServiceName CONNECTOR_CONFIG_SERVICE = JBOSS . append ( "connector" , "config" ) ; public static final ServiceName BEAN_VALIDATION_CONFIG_SERVICE = JBOSS . append ( "connector" , "bean_validation" , "config" ) ; public static final ServiceName ARCHIVE_VALIDATION_CONFIG_SERVICE = JBOSS . append ( "connector" , "archive_validation" , "config" ) ; public static final ServiceName BOOTSTRAP_CONTEXT_SERVICE = JBOSS . append ( "connector" , "bootstrapcontext" ) ; public static final ServiceName TRANSACTION_INTEGRATION_SERVICE = JBOSS . append ( "connector" , "transactionintegration" ) ; public static final ServiceName WORKMANAGER_SERVICE = JBOSS . append ( "connector" , "workmanager" ) ; public static final ServiceName RESOURCE_ADAPTER_SERVICE_PREFIX = JBOSS . append ( "ra" ) ; public static final ServiceName RESOURCE_ADAPTER_DEPLOYMENT_SERVICE_PREFIX = ConnectorServices . RESOURCE_ADAPTER_SERVICE_PREFIX . append ( "deployment" ) ; public static final ServiceName RESOURCE_ADAPTER_DEPLOYER_SERVICE_PREFIX = ConnectorServices . RESOURCE_ADAPTER_SERVICE_PREFIX . append ( "deployer" ) ; public static final ServiceName RESOURCE_ADAPTER_REGISTRY_SERVICE = JBOSS . append ( "raregistry" ) ; public static final ServiceName RESOURCE_ADAPTER_ACTIVATOR_SERVICE = JBOSS . append ( "raactivator" ) ; public static final ServiceName INACTIVE_RESOURCE_ADAPTER_SERVICE = JBOSS . append ( "rainactive" ) ; public static final ServiceName IRONJACAMAR_MDR = JBOSS . append ( "ironjacamar" , "mdr" ) ; public static final ServiceName RA_REPOSITORY_SERVICE = JBOSS . append ( "rarepository" ) ; public static final ServiceName MANAGEMENT_REPOSITORY_SERVICE = JBOSS . append ( "management_repository" ) ; public static final ServiceName RESOURCEADAPTERS_SERVICE = JBOSS . append ( "resourceadapters" ) ; public static final ServiceName RA_SERVICE = JBOSS . append ( "resourceadapters" , "ra" ) ; public static final ServiceName DATASOURCES_SERVICE = JBOSS . append ( "datasources" ) ; public static final ServiceName JDBC_DRIVER_REGISTRY_SERVICE = JBOSS . append ( "jdbc-driver" , "registry" ) ; public static final ServiceName CCM_SERVICE = JBOSS . append ( "cached-connection-manager" ) ; public static final ServiceName IDLE_REMOVER_SERVICE = JBOSS . append ( "ironjacamar" , "idle-remover" ) ; public static final ServiceName CONNECTION_VALIDATOR_SERVICE = JBOSS . append ( "ironjacamar" , "connection-validator" ) ; public static final String RA_SERVICE_NAME_SEPARATOR = "->" ; public static < T > T notNull ( T value ) { } public static Integer getResourceIdentifier ( String raName ) { } public static void unregisterResourceIdentifier ( String raName , Integer identifier ) { } public static synchronized void unregisterResourceIdentifiers ( String raName ) { } private static Integer getDeploymentIdentifier ( String raName ) { } public static synchronized ServiceName registerDeployment ( String raName ) { } public static synchronized ServiceName getDeploymentServiceName ( String raName ) { } public static synchronized void unregisterDeployment ( String raName , ServiceName serviceName ) { } private static Integer getResourceAdapterIdentifier ( String raName ) { } public static synchronized ServiceName registerResourceAdapter ( String raName ) { } public static synchronized void unregisterResourceAdapter ( String raName , ServiceName serviceName ) { } public static synchronized Set < ServiceName > getResourceAdapterServiceNames ( final String raName ) { if ( ( raName == null ) || ( raName . trim ( ) . isEmpty ( ) ) ) { throw MESSAGES . stringParamCannotBeNullOrEmpty ( "resource<seq2seq4repair_space>adapter<seq2seq4repair_space>name" ) ; } ROOT_LOGGER . tracef ( "ConnectorServices:<seq2seq4repair_space>getResourceAdapterServiceNames(%s)<seq2seq4repair_space>-><seq2seq4repair_space>%s" , raName , ConnectorServices . resourceAdapterServiceNames . get ( raName ) ) ; if ( ( ( ConnectorServices . resourceAdapterServiceNames . get ( raName ) ) == null ) || ( ConnectorServices . resourceAdapterServiceNames . get ( raName ) . isEmpty ( ) ) ) { <START_BUG> return null ; <END_BUG> } return Collections . unmodifiableSet ( ConnectorServices . resourceAdapterServiceNames . get ( raName ) ) ; } public static String getRegisteredResourceAdapterIdentifier ( final String raName ) { } public static void registerResourceAdapterIdentifier ( final String raName , final String raIdentifier ) { } public static void unregisterResourceAdapterIdentifier ( final String raName ) { } }

Fix:
return Collections . singleton ( ConnectorServices . RESOURCE_ADAPTER_SERVICE_PREFIX . append ( raName ) ) ;